1. Summary of the Invention
This invention relates to a heat treated latch plate or tongue and, more particularly, to a child's car seat with a T-shield wherein the leading portion of the latch plate is heat treated.
2. Summary of the Background Art
A variety of child car seats have been developed for increasing the safety of children in cars. The most common type of child car seat is one which rests on the vehicle seat and is releasably coupled thereto through the seat belt of the car. Conventional child car seats generally consist of a rigid plastic shell and a padded cover which is provided with its own restraint belt system. Such belt system normally includes a pair of shoulder belts which are adjustable to accommodate the size of the child. The shoulder belts extend downwardly from the shell, across the child, and terminate in a short latch plate or tongue which is releasably received by a buckle fixedly located in the car seat.
A recent advance in child car seats is the use of a T-shield located at the lower ends of the shoulder belts. An elongated latch plate is secured within the lower end of the T-shield. The latch plate is normally fabricated of a rigid material, as for example, a carbon steel. The upper end is fixedly secured within the rigid T-shield while the lower end is provided with a locking aperture for being releasably received by a fixed buckle located in the car seat. The buckle has a release button under the control of a parent or other adult charged with the safety of the child.
It has been found that when latch plates are constructed of a moderately rigid material, as for example a carbon steel which has not been heat treated for increased rigidity, such latch plate can distort under the impact of a crash. When distorted, the latch plate may escape the securement of the buckle and allow the child to be thrown from the seat thereby resulting in injuries. In the alternative, a distorted latch plate may be excessively difficult to separate from the buckle thereby precluding child removal. When, however, the latch plate is entirely heat treated for increased rigidity throughout its entire extent. The impact of a crash may cause a higher degree of load to be transferred to the child, once again increasing the probability of injury to the child.
Various techniques and devices are employed commercially or are disclosed in the patent literature for constituting latch plates for child's car seats. Most of the older types include a lower portion with an aperture for being received by a buckle in combination with a short upper portion with a slot for receiving the shoulder belts. By way of example, note U.S. Pat. Nos. 3,938,859; 4,196,500; 4,301,576; 4,375,714; 4,425,688; 4,566,161; 4,617,705; 4,675,956; 4,733,444 and 4,797,984.
In contrast to the above listed older types of latch plates, newer latch plates have elongated upper portions for being secured with T-shields. Note U.S. Pat. No. 4,342,483 to Takata and U.S. Pat. No. 4,632,460 to Meeker. In these later two patents, however, there is no disclosure with respect to the selective heat treating of only certain portions of the latch plate. It can be assumed, consequently, that the entire latch plate is heat treated, if at all, throughout its entire extent.
As illustrated by the great number of prior patents as well as other commercial devices and techniques, efforts are continuously being made in attempt to improve child car seats and their latch plates. Such efforts have been made to render such devices more safe, reliable, efficient, inexpensive and convenient to use. None of these previous efforts, however, provides the benefits attendant with the present invention. Additionally, the prior patented and commercial devices and techniques do not suggest the present inventive concepts as disclosed and claimed herein.
The present invention achieves its intended purposes, objects and advantages through a new, useful and unobvious combination of component elements, with the use of a minimum number of functioning parts, at a reasonable cost to manufacture, and by employing only readily available materials and techniques.
Accordingly, it is an object of the present invention to provide a child's car seat comprising a rigid frame having back, bottom, and side portions and a buckle located therein; strap means extending from the back over the shoulders of a child occupant of the seat; a T-shield secured to the lower ends of the straps; and a latch plate, the latch plate having an upper portion with an opening adapted to receive the straps and a lower portion with a locking aperture to be releasably secured in the buckle, the upper portion of the latch plate being of a first rigidity and being encompassed and secured within the T-shield and the lower portion of the latch plate being heat treated to render it more rigid than the upper portion.
It is a further object of the present invention to heat treat the lower portion of a latch plate of a T-shield to render it more rigid and less susceptible to distortion during a crash.
It is a further object of the invention to improve the safety of child car seats by rendering the upper portions of T-shields more flexible than their lower portions.
Lastly, it is a further object of the invention to preclude jamming of a latch plate units buckle after a crash.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.